Cisco Systems to Offer Free Reference Implementation of IETF's ISAKMP Security Framework; Encryption software suite to include Cylink cryptographic library.

SAN JOSE, Calif.--(BUSINESS WIRE)--May 6, 1996--Cisco Systems, Inc. today announced the release of free security software to enable secure telecommuting and scalable Virtual Private Networks (VPNs).

This reference implementation enables customers to configure end-to-end IP-layer network security without the burden of manually pre-installed and verified Security Associations. Cisco Systems and Cylink, Inc. are pleased to announce Cisco has purchased the rights to freely distribute the source code to the Diffie-Hellman key exchange, the Digital Signature Standard and the Digital Encryption Standard. This UNIX-based implementation is available to all third parties on a royalty-free basis for use solely with the ISAKMP reference implementation and will assist users in deploying standards-based encryption key management. The software can be downloaded by telneting to port 7600 on ftp-eng.cisco.com.

Cisco and Cylink have a pre-existing relationship for folding Cylink's encryption software technology, the Secure Enterprise Architecture (S.E.A. Stack(TM)), into Cisco IOS(TM) software. Cisco IOS software ensures robust, secure and reliable internetworks by supporting the varied requirements of both LAN and WAN protocols, optimizing WAN services and controlling intranetwork access.

In order to promote the widespread use of these inventions on intranets, the Internet and private networks from Stanford University, and adoption of the ISAKMP reference by the IETF community, Cisco has acquired the right under its sublicense from Cylink to offer the ISAKMP reference implementation to all third parties on a royalty-free basis.

The Cylink cryptographic library is offered under the following licensing conditions:

This software distribution is a reference implementation of the IETF's ISAKMP protocol and is being made available free of charge for any commercial or non-commercial use to advance ISAKMP as a solution to Internet Key Management.

The implementation is based upon ISAKMP draft number 5 (MST96) and utilizes features from the OAKLEY Key Determination Protocol (Orm96). Both documents are quite fluid at the moment and effort is being focused on refining this implementation as the documents mature. The near-term goal is full compliance with both documents. The library does not implement the entire ISAKMP protocol today.

Cylink Corporation, through its wholly owned subsidiary Caro-Kann Corporation, holds exclusive sublicensing rights to the following U.S. patents owned by the Leland Stanford Junior University:

-- Cryptographic Apparatus and Method -- ("Hellman-Diffie")

-- No. 4,200,770

-- Public Key Cryptographic Apparatus and Method -- ("Hellman-

Merkle") -- No. 4,218,582

This royalty-free privilege is limited to use of the ISAKMP reference implementation in accordance with proposed, pending or approved IETF standards and applies only when used with Diffie-Hellman key exchange, the Digital Signature Standard or any other public key techniques that are publicly available for commercial use on a royalty-free basis. Any use of the ISAKMP reference implementation that does not satisfy these conditions and incorporates the practice of public key may require a separate patent license to the Stanford patents, which must be negotiated with Cylink's subsidiary, Caro-Kann Corporation.

This entire distribution is export controlled. It cannot be distributed outside the United States or Canada nor should it be given to a non-citizen or non-permanent resident of the United States. All software in this package is provided under a Disclaimer of Liability.

Cylink (NASDAQ: CYLK), headquartered in Sunnyvale, Calif., is the world's largest provider of a complete line of enterprise-wide information security products and services. Cylink serves Fortune 500 companies, multinational financial institutions and many international government agencies.

Cisco Systems (NASDAQ: CSCO) is the leading global supplier of internetworking solutions for corporate intranets and the global Internet. Cisco's products, including routers, LAN and ATM switches, dial-up access servers and network management software, are integrated by the Cisco IOS software to link geographically dispersed LANs, WANs and IBM networks. Company news and product/service information are available at World Wide Web site http://www.cisco.com. Cisco is headquartered in San Jose, Calif. -0-

Note to Editors: Cisco IOS is a trademark and Cisco, Cisco Systems and the Cisco logo are registered trademarks of Cisco Systems, Inc. Secure Enterprise Architecture(TM) and S.E.A. Stack(TM) are registered trademarks of Cylink Corporation. All other trademarks, service marks, registered trademarks or registered service marks mentioned in this document are the property of their respective owners.

CONTACT: Cisco Systems, Inc.

Adam Stein, 408/526-7388

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or

Cylink Corporation

Paula Dunne, 408/523-5993

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